Some of the fwnode APIs might return an error pointer instead of NULL
or valid fwnode handle. The result of such API call may be considered
optional and hence the test for it is usually done in a form of
fwnode = fwnode_find_reference(...);
if (IS_ERR(fwnode))
...error handling...
Nevertheless the resulting fwnode may have bumped the reference count
and hence caller of the above API is obliged to call fwnode_handle_put().
Since fwnode may be not valid either as NULL or error pointer the check
has to be performed there. This approach uglifies the code and adds
a point of making a mistake, i.e. forgetting about error point case.
To prevent this, allow an error pointer to be passed to the fwnode APIs.
Fixes: 83b34afb6b ("device property: Introduce fwnode_find_reference()")
Reported-by: Nuno Sá <nuno.sa@analog.com>
Tested-by: Nuno Sá <nuno.sa@analog.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add iomap() fwnode operation to implement fwnode_iomap() through fwnode
operations, moving the code in fwnode_iomap() to OF framework.
Note that the IS_ENABLED(CONFIG_OF_ADDRESS) && is_of_node(fwnode) check is
needed for Sparc that has its own implementation of of_iomap anyway. Let
the pre-compiler to handle that check.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If a parent device is also a supplier to a child device, fw_devlink=on by
design delays the probe() of the child device until the probe() of the
parent finishes successfully.
However, some drivers of such parent devices (where parent is also a
supplier) expect the child device to finish probing successfully as soon as
they are added using device_add() and before the probe() of the parent
device has completed successfully. One example of such a case is discussed
in the link mentioned below.
Add a flag to make fw_devlink=on not enforce these supplier-consumer
relationships, so these drivers can continue working.
Link: https://lore.kernel.org/netdev/CAGETcx_uj0V4DChME-gy5HGKTYnxLBX=TH2rag29f_p=UcG+Tg@mail.gmail.com/
Fixes: ea718c6990 ("Revert "Revert "driver core: Set fw_devlink=on by default""")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210915170940.617415-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fw_devlink expects DT device nodes with "compatible" property to have
struct devices created for them. Since the connector node might not be
populated as a device, mark it as such so that fw_devlink knows not to
wait on this fwnode being populated as a struct device.
Without this patch, USB functionality can be broken on some boards.
Fixes: f7514a6630 ("of: property: fw_devlink: Add support for remote-endpoint")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210506004423.345199-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core / debugfs update from Greg KH:
"Here is the "big" driver core and debugfs update for 5.12-rc1
This set of driver core patches caused a bunch of problems in
linux-next for the past few weeks, when Saravana tried to set
fw_devlink=on as the default functionality. This caused a number of
systems to stop booting, and lots of bugs were fixed in this area for
almost all of the reported systems, but this option is not ready to be
turned on just yet for the default operation based on this testing, so
I've reverted that change at the very end so we don't have to worry
about regressions in 5.12
We will try to turn this on for 5.13 if testing goes better over the
next few months.
Other than the fixes caused by the fw_devlink testing in here, there's
not much more:
- debugfs fixes for invalid input into debugfs_lookup()
- kerneldoc cleanups
- warn message if platform drivers return an error on their remove
callback (a futile effort, but good to catch).
All of these have been in linux-next for a while now, and the
regressions have gone away with the revert of the fw_devlink change"
* tag 'driver-core-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (35 commits)
Revert "driver core: Set fw_devlink=on by default"
of: property: fw_devlink: Ignore interrupts property for some configs
debugfs: do not attempt to create a new file before the filesystem is initalized
debugfs: be more robust at handling improper input in debugfs_lookup()
driver core: auxiliary bus: Fix calling stage for auxiliary bus init
of: irq: Fix the return value for of_irq_parse_one() stub
of: irq: make a stub for of_irq_parse_one()
clk: Mark fwnodes when their clock provider is added/removed
PM: domains: Mark fwnodes when their powerdomain is added/removed
irqdomain: Mark fwnodes when their irqdomain is added/removed
driver core: fw_devlink: Handle suppliers that don't use driver core
of: property: Add fw_devlink support for optional properties
driver core: Add fw_devlink.strict kernel param
of: property: Don't add links to absent suppliers
driver core: fw_devlink: Detect supplier devices that will never be added
driver core: platform: Emit a warning if a remove callback returned non-zero
of: property: Fix fw_devlink handling of interrupts/interrupts-extended
gpiolib: Don't probe gpio_device if it's not the primary device
device.h: Remove bogus "the" in kerneldoc
gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default
...
Device links only work between devices that use the driver core to match
and bind a driver to a device. So, add an API for frameworks to let the
driver core know that a fwnode has been initialized by a driver without
using the driver core.
Then use this information to make sure that fw_devlink doesn't make the
consumers wait indefinitely on suppliers that'll never bind to a driver.
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210205222644.2357303-6-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During the initial parsing of firmware by fw_devlink, fw_devlink might
infer that some supplier firmware nodes would get populated as devices.
But the inference is not always correct. This patch tries to logically
detect and fix such mistakes as boot progresses or more devices probe.
fw_devlink makes a fundamental assumption that once a device binds to a
driver, it will populate (i.e: add as struct devices) all the child
firmware nodes that could be populated as devices (if they aren't
populated already).
So, whenever a device probes, we check all its child firmware nodes. If
a child firmware node has a corresponding device populated, we don't
modify the child node or its descendants. However, if a child firmware
node has not been populated as a device, we delete all the fwnode links
where the child node or its descendants are suppliers. This ensures that
no other device is blocked on a firmware node that will never be
populated as a device. We also mark such fwnodes as NOT_DEVICE, so that
no new fwnode links are created with these nodes as suppliers.
Fixes: e590474768 ("driver core: Set fw_devlink=on by default")
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210205222644.2357303-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This function is a wrapper around fwnode_operations.add_links().
This function parses each node in a fwnode tree and create fwnode links
for each of those nodes. The information for creating the fwnode links
(the supplier and consumer fwnode) is obtained by parsing the properties
in each of the fwnodes.
This function also ensures that no fwnode is parsed more than once by
marking the fwnodes as parsed.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-13-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change the meaning of fwnode_operations.add_links() to just create
fwnode links by parsing the properties of a given fwnode.
This patch doesn't actually make any code changes. To keeps things more
digestable, the actual functional changes come in later patches in this
series.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-12-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 716a7a2596.
The fw_devlink_pause/resume() APIs added by the commit being reverted
were a first cut attempt at optimizing boot time. But these APIs don't
fully solve the problem and are very fragile (can only be used for the
top level devices being added). This series replaces them with a much
better optimization that works for all device additions and also has the
benefit of reducing the complexity of the firmware (DT, EFI) specific
code and abstracting out common code to driver core.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-7-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The amount of time spent parsing fwnodes of devices can become really
high if the devices are added in an non-ideal order. Worst case can be
O(N^2) when N devices are added. But this can be optimized to O(N) by
adding all the devices and then parsing all their fwnodes in one batch.
This commit adds fw_devlink_pause() and fw_devlink_resume() to allow
doing this.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200515053500.215929-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fwnode_operations.add_links allows creating device links from
information provided by firmware.
fwnode_operations.add_links is currently implemented only by
OF/devicetree code and a specific case of efi. However, there's nothing
preventing ACPI or other firmware types from implementing it.
The OF implementation is currently controlled by a kernel commandline
parameter called of_devlink.
Since this feature is generic isn't limited to OF, add a generic
fw_devlink kernel commandline parameter to control this feature across
firmware types.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200222014038.180923-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Greg KH:
"Here is the "big" set of driver core patches for 5.5-rc1
There's a few minor cleanups and fixes in here, but the majority of
the patches in here fall into two buckets:
- debugfs api cleanups and fixes
- driver core device link support for boot dependancy issues
The debugfs api cleanups are working to slowly refactor the debugfs
apis so that it is even harder to use incorrectly. That work has been
happening for the past few kernel releases and will continue over
time, it's a long-term project/goal
The driver core device link support missed 5.4 by just a bit, so it's
been sitting and baking for many months now. It's from Saravana Kannan
to help resolve the problems that DT-based systems have at boot time
with dependancy graphs and kernel modules. Turns out that no one has
actually tried to build a generic arm64 kernel with loads of modules
and have it "just work" for a variety of platforms (like a distro
kernel). The big problem turned out to be a lack of dependency
information between different areas of DT entries, and the work here
resolves that problem and now allows devices to boot properly, and
quicker than a monolith kernel.
All of these patches have been in linux-next for a long time with no
reported issues"
* tag 'driver-core-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (68 commits)
tracing: Remove unnecessary DEBUG_FS dependency
of: property: Add device link support for interrupt-parent, dmas and -gpio(s)
debugfs: Fix !DEBUG_FS debugfs_create_automount
of: property: Add device link support for "iommu-map"
of: property: Fix the semantics of of_is_ancestor_of()
i2c: of: Populate fwnode in of_i2c_get_board_info()
drivers: base: Fix Kconfig indentation
firmware_loader: Fix labels with comma for builtin firmware
driver core: Allow device link operations inside sync_state()
driver core: platform: Declare ret variable only once
cpu-topology: declare parse_acpi_topology in <linux/arch_topology.h>
crypto: hisilicon: no need to check return value of debugfs_create functions
driver core: platform: use the correct callback type for bus_find_device
firmware_class: make firmware caching configurable
driver core: Clarify documentation for fwnode_operations.add_links()
mailbox: tegra: Fix superfluous IRQ error message
net: caif: Fix debugfs on 64-bit platforms
mac80211: Use debugfs_create_xul() helper
media: c8sectpfe: no need to check return value of debugfs_create functions
of: property: Add device link support for iommus, mboxes and io-channels
...
The add_links() ops shouldn't return on the first failed device link
add. It needs to continue trying to add device links to other suppliers
that are available. The documentation didn't explain WHY this behavior
is necessary. So, update the documentation with an example that explains
why this is necessary.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191011191521.179614-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
